1. Field of the Disclosure
The disclosure relates generally to apparatus and methods for control of fluid flow from subterranean formations into a production string in a wellbore.
2. Description of the Related Art
Hydrocarbons such as oil and gas are recovered from subterranean formations using a well or wellbore drilled into such formations. In some cases the wellbore is completed by placing a casing along the wellbore length and perforating the casing adjacent each production zone (hydrocarbon bearing zone) to extract fluids (such as oil and gas) from such a production zone. In other cases, the wellbore may be open hole, and in a particular case may be used for injection of steam or other substances into a geological formation. One or more, typically discrete, flow control devices are placed in the wellbore within each production zone to control the flow of fluids from the formation into the wellbore. These flow control devices and production zones may be active or passive and are generally fluidly isolated or separated from each other by packers. Fluid from each production zone entering the wellbore typically travels along an annular area between a production tubular that runs to the surface and either a casing or the open hole formation and is then drawn into the production tubular through the flow control device. The fluid from a reservoir within a formation (“reservoir fluid”) often includes solid particles, generally referred to as the “sand”, which are more prevalent in unconsolidated formations. In such formations, flow control devices generally include a sand screen system that inhibits flow of the solids above a certain size into the production tubular.
It is often desirable also to have a substantially even flow of the formation fluid along a production zone or among production zones within a wellbore. In either case, uneven fluid flow may result in undesirable conditions such as invasion of a gas cone or water cone. Water or gas flow into the wellbore in even a single production zone along the wellbore can significantly reduce the amount and quality of the production of oil along the entire wellbore. Flow control devices may be actively-controlled flow control valves, such as sliding sleeves, which are operated from the surface or through autonomous active control. Other flow control devices may be passive inflow control devices designed to preferentially permit production or flow of a desired fluid into the wellbore, while inhibiting the flow of water and/or gas or other undesired fluids from the production zones. Sand screens utilized in production zones typically lack a perforated base pipe and require the formation fluid to pass through the screen filtration layers before such fluid can travel along the annular pathway along approximately the entire length of the production zone before it enters the production tubular at a discrete location.
Horizontal wellbores are often drilled into a production zone to extract fluid therefrom. Several flow control devices are placed spaced apart along such a wellbore to drain formation fluid. Formation fluid often contains a layer of oil, a layer of water below the oil and a layer of gas above the oil. A horizontal wellbore is typically placed above the water layer. The boundary layers of oil, water and gas may not be even along the entire length of the horizontal wellbore. Also, certain properties of the formation, such as porosity and permeability, may not be the same along the horizontal wellbore length. Therefore, for these and other reasons, fluid between the formation and the wellbore may not flow evenly through the inflow control devices. For production wellbores, it is desirable to have a relatively even flow of the production fluid into the wellbore. To produce optimal flow of hydrocarbons from a wellbore, production zones may utilize flow control devices with differing flow characteristics.
A common type of sand screen is known as a “wire wrapped screen”. Such sand screens generally are formed by placing standoffs axially on a tubular and then wrapping a wire around the standoffs. The closely controlled spacing between adjacent wire wraps defines the grain sizes inhibited from flowing through the sand screen. Conventional discrete flow control devices are expensive and can require substantial radial space, which can reduce the internal diameter of the production tubing available for the production or flow of the hydrocarbons to the surface. Also, the typical single entry point along a production zone is inefficient and if there is an encroachment of sand or other particles larger than the spacing between the wire wraps, the annular flow area within the sand screen system could become blocked, thereby limiting the production of formation fluid from the entire production zone.
The present disclosure provides flow control devices and methods of using the same that enable flow of formation fluids radially from a production zone into the production tubular and may optionally include an integrated sand screen.